Can romex condcutors be installed in emt?

[Eric R 1973]

I have 5 circuits, 4 of which are 12/2, and one is 14/2. The circuits go from the attic, down a pipe chase, to the basement, which has a finished ceiling. I want to install the romex (after stripping the sheathing off) in 3/4 emt, and run it back to the panel.

See Chapter 9 tables 4 and 5 I think it's type TW insulation

 

[roger]

See Chapter 9 tables 4 and 5 I think it's type TW insulation

Eric, the conductors inside NM have no designation, they are 90 deg insulation but this can only be used for derating purposes.

BTW, welcome to the forum.

Roger

 

[dana1028]

Stripping NM cable sheathing

Stripping NM cable sheathing

I personally asked UL about stripping sheathing off NM for conduit runs.

Their reply - this violates the listing of the 'assembly.' NM is listed as an assembly, once you strip off the sheathing for conduit runs you have 'field modified' the product.

UL referred me to pg. 41 [2010 UL White Book] - FIELD MODIFICATIONS.

IE - No - you cannot strip the sheathing off NM for conduit runs.

 

[tallgirl]

Why would anyone WANT to strip that much Romex just so they can run it through a piece of pipe? Get something more manageable -- like stranded THHN -- and fish that.

 

[iwire]

I personally asked UL about stripping sheathing off NM for conduit runs.

Their reply - this violates the listing of the 'assembly.' NM is listed as an assembly, once you strip off the sheathing for conduit runs you have 'field modified' the product.

UL referred me to pg. 41 [2010 UL White Book] - FIELD MODIFICATIONS.

IE - No - you cannot strip the sheathing off NM for conduit runs.

Nothing personal and I am sure what the 'UL person' said but I am not buying it.

For one, if we cannot strip NM that will be an issue at each box, unless you can show me where there is something written saying striping to enter a box, fixture or cabinet is OK but not for a raceway.

Secondly it is the AHJs responsibility to determine if field modifications have altered the product enough to require field inspections.

The following is directly from the UL white book.

What happens to the Listing if a UL-Listed product is modified in the field?

An authorized use of the UL Mark is the manufacturer?s declaration that the product was originally
manufactured in accordance with the applicable requirements when it was shipped from the factory. When
a UL-Listed product is modified after it leaves the factory, UL has no way to determine if the product
continues to comply with the safety requirements used to certify the product without investigating the
modified product. UL can neither indicate that such modifications ??void?? the UL Mark, nor that the
product continues to meet UL?s safety requirements, unless the field modifications have been specifically
investigated by UL. It is the responsibility of the Authority Having Jurisdiction (AHJ) to determine the
acceptability of the modification or if the modifications are significant enough to require one of UL?s Field
Engineering Services staff members to evaluate the modified product. UL can assist the AHJ in making this
determination.

 

[iwire]

Why would anyone WANT to strip that much Romex just so they can run it through a piece of pipe? Get something more manageable -- like stranded THHN -- and fish that.

I have to assume you have not worked on a lot of jobs that use both NM and EMT. Picture you run 100' of NM through a building but once you get to the electrical room you must change to pipe. Is it easier (or even possible) to add a J-box to change to THHN or just change directly to pipe with a fitting without a splice?

 

[dana1028]

Nothing personal and I am sure what the 'UL person' said but I am not buying it.

For one, if we cannot strip NM that will be an issue at each box, unless you can show me where there is something written saying striping to enter a box, fixture or cabinet is OK but not for a raceway.

Secondly it is the AHJs responsibility to determine if field modifications have altered the product enough to require field inspections.

The following is directly from the UL white book.

I agree with you 100%.

With UL's position that NM has been field modified, and my authority [as an inspector] to make a determination, I reject such an installation. At our local electrical inspector meetings such position is in consensus [UL attends our meetings].

 

[roger]

I personally asked UL about stripping sheathing off NM for conduit runs.

Their reply - this violates the listing of the 'assembly.' NM is listed as an assembly, once you strip off the sheathing for conduit runs you have 'field modified' the product.

UL referred me to pg. 41 [2010 UL White Book] - FIELD MODIFICATIONS.

IE - No - you cannot strip the sheathing off NM for conduit runs.

I agree with you 100%.

With UL's position that NM has been field modified, and my authority [as an inspector] to make a determination, I reject such an installation. At our local electrical inspector meetings such position is in consensus [UL attends our meetings].

So, if I strip the sheath off of MC and use the conductors as they are marked I have modified a cable assembly, would you reject that and how would you know that the conductors came out of an assembly?

I can understand rejecting an installation based on 310.11 but, we have to modify every cable assembly we hook up so UL has missed the boat if that is their stance.

But of course UL would let us remove all the concentric KO rings and use reducing washers to get around using a bond bushing.

Roger

 

[iwire]

I agree with you 100%.

With UL's position that NM has been field modified, and my authority [as an inspector] to make a determination, I reject such an installation. At our local electrical inspector meetings such position is in consensus [UL attends our meetings].

Typically the Inspector is not the AHJ.

What is the safety issue you see with striping the jacket and why is it wrong in a raceway but OK in a panel?

 

[LarryFine]

With UL's position that NM has been field modified, and my authority [as an inspector] to make a determination, I reject such an installation.

Where do you draw the line? What about where NM terminates in outlet and J-boxes, or disconnects, or the exposed wire in troughs or gutters, or the 3 or 4' of wire exposed in panels?

What about wire used to extend existing wires, such as done in a service upgrade, where the old wires won't reach the new breakers? What about pigtails in multi-gang switch boxes?

 

[glene77is]

because a panel is not a raceway?

Electrical Load Center (Circuit Breaker Panel) can be a raceway for feed-thru,
as long as the volume requirments of 40% & 70% are maintained.

 

[tallgirl]

I have to assume you have not worked on a lot of jobs that use both NM and EMT. Picture you run 100' of NM through a building but once you get to the electrical room you must change to pipe. Is it easier (or even possible) to add a J-box to change to THHN or just change directly to pipe with a fitting without a splice?

The comment was about running NM -- stripped no less -- through pipe for the entire job. I didn't read anything other than pipe and more pipe.

 

[iwire]

You had asked why you would want to run NM (or cable) in a raceway, I was simply giving you a common scenario.

Another is placing receptacles on dwelling unit unfinished basement walls. You run NM all around stapled to the joists and where you drop down the unfinished wall you place the NM in a raceway.

 

[tallgirl]

You had asked why you would want to run NM (or cable) in a raceway, I was simply giving you a common scenario.

Another is placing receptacles on dwelling unit unfinished basement walls. You run NM all around stapled to the joists and where you drop down the unfinished wall you place the NM in a raceway.

For sure, in those examples. I was just saying if the OP was going to go to the bother of stripping NM to run in pipe from attic to basement, use something that came unsheathed to start with ...

 

[glene77is]

For sure, in those examples.
I was just saying if the OP was going to go to the bother of stripping NM to run in pipe from attic to basement,
use something that came unsheathed to start with ...

Tall,
Good point.

IMO, maybe strip off the NM, for a complete run,
just for the convenience of not carrying a supply of THHN on several spools.

 

[iwire]

For sure, in those examples. I was just saying if the OP was going to go to the bother of stripping NM to run in pipe from attic to basement, use something that came unsheathed to start with ...

Maybe that is all they had in the truck, maybe they like the feeling of using a knife, maybe they are just messed up in the head but none of that addresses the question that was asked does it?

 

[tallgirl]

Maybe that is all they had in the truck, maybe they like the feeling of using a knife, maybe they are just messed up in the head but none of that addresses the question that was asked does it?

I thought the question was answered straight away -- "No".

 

[Jim W in Tampa]

There is 1 violation as the wires will not have the required marking anymore. Would I do it YES if it is the truck answer. See it as hazard NO

 

[tallgirl]

I can't imagine that the extra cost to print the individual wires would make any real difference in the end cost. We are talking about extra pennies per thousands of feet.

Besides, wouldn't that make for a minor competitive edge for someone that did it that way?

There is no such thing in commodity pricing as not making "any real difference in the end cost." If it costs money, either you reduce your margins (can be a bad idea) or your increase your price (can also be a bad idea). 12/2 NM is a commodity. ESPECIALLY 12/2.

 

[tallgirl]

There is 1 violation as the wires will not have the required marking anymore. Would I do it YES if it is the truck answer. See it as hazard NO

Yup.

It's the same as PV installers who use "welding wire" for battery connections instead of whatever the actually required wire is. Works great, doesn't seem to be a hazard, still not the correct wire.